1. Field of the Invention
The invention relates to a rotation hinge, and particularly to a rotation hinge configured in a portable electrical device capable of allowing a sub-housing of the portable electrical device rotating on a main housing of the portable electrical device.
2. The Related Art
According to the current development of communication technology, portable electrical devices such as mobile phones, personal digital assistants and others, are capable of providing wireless communication. One kind of the portable electrical devices includes a rotation-type configuration. The rotation-type configuration has a rotation hinge configured therein capable of allowing a sub-housing of the portable electrical devices rotating on a main housing of the portable electrical devices. In consideration of carrying and downsizing issues, the sub-housing rotates above the main housing to an open position for the operation purpose. Otherwise, the sub-housing rotates to cover the main housing to a close position for an idle or standby situation.
There is a rotation-type wireless communication device disclosed in United States Patent Application Publication No. 2004/0018862. It shows the wireless communication device including a first housing with a housing support and a second housing positioned upon the housing support, or a portion thereof, so that the second housing may rotate around the housing support. Also, the second housing includes a circular portion positioned upon the housing support, and an extending portion extends from the circular portion. When the device is in a closed position, the circular and extending portions of the second housing are adjacent to the first housing. When the device is in an opened position, the circular portion is adjacent to the first housing and the extending portion is away from the first housing. In addition, the second housing may have multiple positions relative to the first housing in which each position activates a particular function of the device.
However, the above described rotation-type wireless communication device generally needs to be opened and closed by separately gripping each housing portion and repositioning or rotating the housing portion relative to one another. This generally requires that the user free up both hands for opening the rotation-type wireless communication device. Consequently, there is a need for a self-operating opening and closed mechanism for configuring in a hand-held portable electrical device to make the housing portion self-rotating to one another.